The invention relates to a reciprocating piston combustion engine for vehicles of the type having fuel injection nozzles and water injection nozzles installed in the suction pipe arrangement, which nozzles are all electromagnetically operated.
According to the known combustion engine from the German published application (DE-AS) No. 1 115 518, the fuel and water are separated and injected with respective nozzles into the combustion space in order to improve the combustion process through the achieved dissociation of the split products.
On the other hand, the water injection should only result in an inner cooling, in order to avoid thermal damage occurring through short duration high loadings, exemplary resulting from accelleration for passing another motor vehicle or during the start of an airplane.
The problem of the invention consists in developing a suitable water injection for the fuel volume with constructively simple means and minimal assembly costs.
In order to solve this problem, the present invention provides at least one electromagnetic water injection valve controlled by the same commercially available electronic injection control device connected to the fuel injection valves in the same phase or cycle as the fuel injection valves. With a six cylinder motor with six injection valves, the valves are divided into two sets of three fuel injection valves and one water injection valve respectively. Because the duration of the injection time for all valves is similar and all are operated in a cycle sequence, the relationship between the injected fuel volume to the water volume is 3:1, which ratio is a proven desired arrangement for practical embodiments of the combustion engines. For a six cylinder engine, it is a very simple matter to utilize an injection control which is designed to be used for an eight cylinder combustion engine and simply substituted two water injection valves which are supplied with a water supply line or connection for two of the fuel injection valves.
For an eight cylinder combustion engine, three or four water injection nozzles are advantageously used so that the volume comparison to the fuel is in one case 25% and in the other case 50%.
Since the water injection is only necessary for a short duration during high loading conditions of the combustion engine, a water enabling device is used. In one embodiment, the water inlet to the water injection valve can be interrupted by the shutting off of the water pump for the water injection valves. Alternatively, the electrical connection from the control device to the water injection nozzle includes a switch built in, which institutes the water injection according to the closing position thereof. This switch, as well as the switch for the water pump, can be controlled independently by the load, the loading pressure or the temperature of the combustion engine, in order to achieve an automatic switching on of the water injection under thermally dangerous operation of the machine or controlled manually.
The water injection valves can be arranged on each of the respective inlet manifolds of the cylinders. With a combustion engine with turbocharger, it is contemplated to place the same at the inlet or pressure side of the compressor. In this manner, there will occur a fine water diffusion or atomization in the rotating airstream, which will achieve a dampening in the warm changing air and a cooling of the charging air. With such an arrangement, there will be achieved a fuel saving in conjunction with higher loads.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.